Presented at: University of Venda, South Africa
30 April 2021
Luminescence = is production of light through excitation by means other than increasing temperature
Fluorescence is a short-lived type of luminescence created by electromagnetic excitation /light /photons
Fluorescence occurs when an photons (light energy) raises an electron’s energy state (excitation) and the electron undergoes rapid thermal energy loss (vibration) to a singlet energy state and light (photon) is emitted as a by-product of it returning to its ground state
Measures:
CD4 absolute count
CD4 percentage of lymphocytes
Hemoglobin concentration in human whole blood
The inside of the cartridge is coated with the following antibodies:
The CD4 is a molecule found on a subset of immune cells within blood.
It acts as a receptor for human immunodeficiency virus (HIV) to gain entry into cells.
CD3 APC and CD45RA APC = total lymphocytes.
CD4 PE-Cy5 = CD4 lymphocytes.
Spectrophotometry is the measurement of the intensity of light at selected wavelength
The method depends on the light absorbing property of the substance being analysed
The light absorption is directly related to the concentration of the compound in the sample.
As Concentration increases, light absorption increases linearly and light transmission decreases, exponentially
Evaluate and monitor the immune status of patients diagnosed with, or suspected of developing, immune deficiencies such as acquired immune deficiency syndrome (AIDS).
The number of CD4 T lymphocytes declines in HIV infection. Moreover, absolute number and percentage of CD4 T lymphocytes are the cellular parameters most closely associated with HIV disease progression and patient prognosis
Haemoglobin is a protein in red blood cells that carries oxygen from the lungs to the body.
Low or declining haemoglobin concentration is an indicator of anaemia, a hematological abnormality frequently associated with HIV
BD FACSPresto™ Cartridge manual
Behlke M.A., Huang L., Bogh L., Rose S. and Devor E.J. (2005). Fluorescence and Fluorescence Applications. Integrated DNA Technologies.
Fluorescence spectrophotometry as applied in BD FACSPresto™ Near-Patient CD4 Counter